52 
EOTAL IIORTICULTUEAL SOCIETY. 
xi. Achillea Millefolium. 
Box 1. In this box the plants were much matted together ; and 
the individuals therefore varied in size and vigour ; moreover, in 
some instances, the olfshoots or stolons had given rise to new 
plants, which had become independent by the decay of the offshoot. 
The main stem was terminated by a flower-stalk, which died down 
?ifter flowering, so that the growth of the stem is " determinate." 
The formation of lateral shoots is therefore imperative if the 
plant is to persist a second season. These lateral shoots are 
of two kinds : the one, which may be called stock-branches, are 
mere subdivisions of the stock or rhizome ; the others are long 
slender runners, each terminated by a new crown, which ultimately 
is detached from the main stock by the decay of the runners, and 
forms an independent plant. In most cases the primary root 
remained in the form of a woody flexuous tap-root, 6-8 inches 
long, giving off here and there a few short fibrils ; but in some 
instances the primary embryonic root speedily decayed, so that 
the roots with which the adult plant was furnished were Avholly 
adventitious and proceeded from the short woody stock. 
Box 2. More vigorous than no. 1. Eunners not so numerous, 
shorter, but much firmer and more woody than in no. 1. Main or 
primary roots almost all present, cylindrical, as thick as a crow- 
quill, flexuous, descending vertically, 12-14 inches long ; adventi- 
tious roots 6-7 inches long. 
Box 3. More vigorous than 2 both in regard to runners and 
roots (the runners especially). Stocks slightly branched. Main 
root 16-18 inches long ; adventitious roots 8 inches long ; runner, 
in one case, 18 inches long. 
Box 4. More vigorous than 1, 2, and 3, both in regard to roots 
and runners ; the latter, however, are softer than in 3. Stock- 
branches numerous. Main roots 14-16 inches long ; adventitious 
roots 7-8 inches long. 
- Box 5. The most vigorous of all. Branches of stock thick, 
woody, with numerous adventitious roots. Eunners numerous, 
soft, 10-12 inches long, with a few short fibrils. Main root 14- 
16 inches long, thicker and more woody than in all the rest; ad- 
ventitious roots 1 inch long. 
Box 6. Inferior to 5 and 4, superior to the rest. Stock- 
branches shorter and not so stout as in 4. Eunners 12-14 
inches long, soft in texture. Main root 16-18 inches long ; ad- 
ventitious roots 4 inchcR. 
